1. Field of the Invention
This invention relates to a disk driving device for recording or reproducing information on or from a disk, and more particularly to a seek mechanism included in the disk driving device.
2. Description of the Related Art
The disk driving device of the kind driving a disk-shaped recording medium such as a magnetic disk or a laser disk for recording or reproducing information on or from the disk is generally arranged to permit insertion and ejection of the disk, to drive the disk to rotate by a motor, and to permit recording or reproduction by moving a head in a state of being in contact with or very close to the disk. The head is mounted on a carriage and is arranged to be moved (for seeking) by a motor along the surface of the disk in the radial direction of the disk.
The conventional disk driving device has various parts arranged on a base, including inserting/ejecting means for mounting and demounting a disk cassette, disk rotation driving means for rotating the disk by a motor, head seek means for radially moving the head over the disk to the position of a desired recording track, and head loading means for loading or unloading the head on or from the disk. The disk driving device is provided further with a control circuit for controlling the whole disk driving device, a connector for connecting a power supply, etc. The control circuit is connected via an interface to some external equipment such as a host computer, etc.
The disk driving device of this kind is employed sometimes as an independent external storage device for an electronic apparatus such as a personal computer or a word processor. However, the disk driving device is generally incorporated into the body of electronic equipment. As efforts are being exerted in general for reduction in size of the electronic apparatus for portability, a reduction in size, weight and thickness of the disk driving device is now strongly desired.
Further, as a result of diversification of the personal computers and the word processors, a posture in which the disk driving device is to be incorporated in each of such apparatuses has come to be changed from the conventional horizontal posture, for example, to a slanting or vertical posture.
FIGS. 1, 2 and 3 of the accompanying drawings show a head driving mechanism of the conventional disk driving device respectively in oblique, plan and side views. As shown, a head 1 is mounted on a head carriage 2. The head carriage 2 is movably carried by a fixed guide bar 3. An engaging pin 4 is integrally secured to the head carriage 2. The engaging pin 4 engages the lead groove 5a of a lead screw 5 which is arranged in parallel to the guide bar 3. A leaf spring 6 which is provided on the head carriage 2 is arranged to cause the engaging pin 4 of the head carriage 2 to engage the lead groove 5a of the lead screw 5 without fail by pressing the lead screw 5 against the engaging pin 4. With the head driving mechanism arranged in this manner, if the disk driving device is vertically arranged, an engagement play .delta. which exists at a point R between the head carriage 2 and the guide bar 3 as shown in FIG. 2 causes the head carriage 2 to be slanted by its own weight on an engaging point O of the engaging pin 4 and the lead groove 5a. The head 1 also slants to a degree .DELTA.T which corresponds to the ratio of a distance from the engaging point O to the head 1 to a distance from the engaging point O to the point R. This slant has presented a problem that a track position, as defined by the head 1 deviates from its correct position.